Erin Williams alerted me to changes in the United Nations Treaty Collection website. The links I had provided in an earlier post are no longer working.
The titles of multilateral treaties deposit with the Secretary General in the UN official languages may be found here.
I would suggest that you visit the UN Treaty Collection website (now in English and French only) for further information. It is a much improved website with full-text search in English and French.
Erin also provided this useful link.
Thanks for the tip, Erin!